Alkyl (1-p-menthen-6-yl) ketones and process therefor



United States Patent 3,007,967 ALKYL (1-p-MENTHEN-6-YL)KETONES ANDPROCESS THEREFOR Patented Nov. 7, 1961 The desired reaction product isrecovered from the re action mixture by adding water to the reactionmixture in order to decompose and dissolve the zinc chloride from theformed complex and to free the desired ketone which Habib EmileEschinazi, now by judicial change of 5 Separates as a top layer i EnllleHavlv Eschlmlsl Montclalr asslgnor It is believed particularlynoteworthy that while all of 0 The Givaudan Corporation, New York, N.Y.,a corh hi h Duration of New Jersey t e compounds of this invent onpossess propertles w c No Drawing. Filed Sept. 19, 1958, Ser. No.761,942 make, them sultab'le far Perfumery, the aioresald 8 C (C 2 0 537reaction products where R 18 ethyl or propyl possess cspeciallydesirable olfactory characteristics, the product This invention relatesto novel chemical compounds where R is ethyl being especiallynoteworthy. and to a process for preparing them. In order more clearlyto describe this invention the The compounds and process which form thesubject of following examples are given, it being understood that thisinvention may be represented by the following equathey are for purposesof illustration and not for purposes tion: 5 of limitation.

CH, CH, EXAMPLE I (3\ (J\ Preparation of methyl(l-p-menthen-d-yl)-ket0ne H CH2 HC CHC R+R Into a solution of 300 g. ofanhydrous Zinc chloride ,3; E 20 in 2.60 g. of acetic anhydride, 275 g.of l-p-menthene, CH (n 1.45 68; u +95), are added within 30 minutes at(h (h a temperature around 3038 C. The mixture is then H H stirred foran additional 2 hours. Then 600 ml. of water Q, are added and themixture is stirred for 15-20 minutes. whe l The top layer is thenseparated, neutralizedwith 10% Iri g iie sal j ihz g io cii sis o f ibii s invention involves treat- *I t Soda Separated again and dlstlnefiA ing l-p-menthene with an aliphatic acid anhydride in the t iractlon lz ig i t fii f to presence of a suitable catalyst at a temperaturearound 'o z g e e 1S 0 ag E 164 room temperature. As anhydrides whichmay be used d h 2 f fi l mermzrytp essure an 8 the following are noted:acetic anhydride, propionic anan as t e 0 Owing cons an 5- hydride andbutyric anhydi'ide. Condensing catalysts, 11 1.4712; OLD17, d=.9188ketone, by such as zinc chloride, sulfuric acid or phosphoric acid,oximation 96% p? used p chlorilie is Preferred as it enables i A residueof about 53 g. is left in the flask. obtaining of optically-activeproducts when the starting 1-p-menthene is optically active. Also,unlike the cases EXAMPLE H where condensing agents such as sulfuric acidor phospreparation of phone acid are employed, the use of Zinc chlorideresults i in the substantial absence of conjugated reaction prod- Into5011mm} 400 P anhydrous Z111: chloride m ucts as respects the doublebond in the nucleus and the 40 of proplongc anhydrlde 1,000 ofl'pmentheflei carbonyl group of the ide h i 14568, (x 95 as obtainedfrom the hydrogenation If desired, the reaction may be conducted in thePres of d -11monene with Raney nickel, is slowly introduced ence ofSuitable S01,vemS within flS minutes around 30 C. Agitation of the reac-The concentrations of the materials employed in the tlon mixture ismaintained for an additional 3 hours. process of this invention may bevaried Over Wide whim Then 1.5 hters of water are 1ntroduced within 5-10min- In general, it has been found that the Permissive and PM? utes andthe agitation continued for another half hour. ferred amounts are as setforth in the following table, standmg f a mmutes the top layer P P itbeing understood that the pal-ts in moles: and washed twice with 1 literof water under agltation for h 5 more minutes. The top layer is thenneutralized with Permissive P f r d a 10% aqueous caustic soda solutionuntil neutral and Range Range then separated. One liter of 20% aqueouscaustic soda is then added to the resulting top layer; and the mixturesf g- 3533 i 1 H heated to reflux for 3 hours by which time most of thecatal st--IIIIIIIIIIIII I: 0.1-2 014-015 halogenated impurities areeliminated- Upon distillation of the separated top layer the follow-With respect to the conditions under which the hereining cuts areobtained; the pressures being in mm. of Hg described process isconducted, it may be said that a temand the temperatures in C.:

Out B.P. G. m: an Ketone, Ester,

percent percent 1. Lowboillng. 16 mm./67 150 jl.45201.4580 +15-0 5 0 2Intermediate 3 mm.l4574. 100 1 45804.4680. 20 to 70 30 a sin 3mm./88-89650 1 wee-1.4710- --so to -40 94-99 5-1 4. Intermediate.. 3 mm./-95 901.47201.4740- -30 to +20 98-99 1 5. High boiling".-- 3111111.]-110" e01.4750-1A800 +20 to +40 40-50 6. Residue 100 viscous polymer Cut 1 isconstituted mainly of racemized l-p-menthene. Cut 2 isthe ketone mixedwith a substantial amount of ester (30%) as the propionate and maycontain some halogenated impurities. It may be retreated with causticsoda to recover the desired ketone.

Cut 3 is the main out which possesses a characteristic odor of neroliand bergamot and can be used as such.

Cut 4 is also 98-99% pure ketone of good odor. It is partially racemizedand should be treated once more with caustic soda if it shows signs ofhalogen impurities. Cut 5 may contain some traces of halogens; It ispale yellow in color and shows about 40% ketone content with asubstantial amount of a terpene dimer. It may be retreated with causticsoda and redistilled to recover the ketone.

When the reaction is carried with racemic l-p-menthene also known ascarvomenthene the reaction product is devoid of any optical activity,but is otherwise the same as the one obtained when d-l-p-menthene isused.

species of orange tree leaves and twig ends and known as oil petitgrain.This note persisted about forty-eight hours attenuating slowly afterfive hours.

A mixture was made with 1 part of the compound made in accordance withthis example and 99 parts of white milled toilet soap stock. The soapstock odor EXAMPLE III Preparation of I-(J-p-menthen-yl)-J-butanone Intoa solution of 300 g. of anhydrous zinc chloride in 410 g. of butyricanhydride is added in the course of 30 minutes 275 g. of l-p-menthene(11 1.4568; a +95) at a temperature of 30-35 C. The reaction mixture andthe temperature neutralized with After separation,

35, ketone by nounced horse stable After about one hour the odor becamemore animal like and attenuated rapidly. It still persisted aboutforty-eight hours.

When incorporated in the aforesaid soap stock in the unts used inaccordance with Example II, it was soap is about 10 I Example III.

It will be understood that the specification and claims herein include,whenever the context so admits or requires not only the racemic forms ofthe novel compounds herein described but also their optically-activeforms.

by the fol- CHCOR CH CH wherein R is a lower alkyl radical.

2. The chemical compound, methyl (l-p-menthen-6- yl)-ketone having thefollowing structural formula:

CHCOCH;

C CH3 3. The chemical compound, 1-(1- -menthen-6-yl)-1- propanone,having the following structural formula:

CHCO 02H;

H2 CH2 5. The process for making compounds represented by the followingstructural formula:

CHCOR wherein R is a lower reacting l-p-menthene of the formula, (RCO)O, wherein R is a lower alkyl group, in the presence of temperaturewithin the range from about 0 C. to about 50 C.

6. The process for making methyl (l-p-menthen-6-yl) ketone, whichcomprises reacting l-p-menthene and acetic anhydride in the presence ofanhydrous zinc chloride at a temperature within the range from about 0 Cto about 50 C.

7. The process for making 1-( l-p-menthen-6 yl)-1- propanone, whichcomprises reacting l-p-menthene and propionic anhydride in the presenceof anhydrous ing :hloride at a temperature within the range from aboutReferences Cited in the file of this patent Y) to about 500 Colonge etaL: Bull. Soc. Chim. (France), v01. 7,

8. The process for making 1-(1-p-menthen-6-yl)-1- pages 459 g 194butanone, which comprises reacting l-p-menthene and cglonge et 1; Ch m,Abstracts, v01. 36, pages butyric anhydride in the presence of anhydrouszinc 5 2842-3 (1942). chloride at a temperature within the range fromabout 0 Royals st 211.: J. Org. Chem, v01. 15, pages 1147-54 C. to about50 C. (1950).

' Est-Tom? JOHN-sow UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No. 3,007,967 November 7, 1961 Habib Emile Eschinazi nowby judicial change of name Emile Haviv Eschinasi 1 It is herebycertified that error appears in the above numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

Column 1, lines 16 to 25, the left-hand. portion of the formula shouldappear as shown below instead of as in the patent:

CH CH Signed and sealed this 24th day of April 1962f.

(SEAL) Attest:

DAVID L. LADD Commissioner of Patents Attesting Officer

1. THE CHEMICAL COMPOUNDS REPRESENTED BY THE FOLLOWING STRUCTURALFORMULA: